Technical Notes

Note on beams used on 30 and 40 meter bands:

These bands are considered a "bonus" with our multi-band beam antennas. The performance of our beams is usually equivalent to or better than a dipole at the beam height. Over distances
of 4000 miles and greater, their performance on these two bands is similar to (or
better than) a quarter-wave ground plane with 18 radials. The receive
noise level is significantly better with our antenna than a with vertical.

The feed point impedance of a 40-meter antenna varies widely with height above ground. Due to
this variation in impedance, some difficulty may be experienced in tuning the antenna
for 30 and 40 meters. The presence of metal structures and other antennas in close
proximity to the beam may also affect tuning of the beam.

Feedline:

It is very important to use a high quality MIL Spec 50 or 52 ohm
coax cable with the Sommer antenna. RG213U or RG217U are recommended,
due to their high mechanical stability.

Balun:

The balun furnished with the Sommer antennas is a low-loss air core type using RG142
(BU) Teflon cable. The balun will handle 2.9 kW continuous output at 30 MHz with a loss
of only 0.05 dB.

Note:

In the interest of technical improvement, all specifications are subject to change without notice or obligation.

XP404

Basic Model

10-12-15-20 m

$ 749

XP504

Basic Model

10-12-15-20 m

$ 999

XP704

Basic Model

10-12-15-20 m

$1249

XP804

Basic Model

10-12-15-20 m

$1600

Expansion Kits
(Prices valid only when ordered together with beam)

17 m Kit

$200

30 m Kit *

* 30 m kit is not possible at XP40 series beams

$ 60

40 m Kit

$ 60

6 m Kit

$ 50

Note:
The last number of the model number (e.g. XP704, XP706, XP707) indicates
the number of the bands covered.
XP40 and XP50 series booms are self supporting. XP70 and XP80 booms
need to be guyed.
Non-cunductive UV-resistant guy and bracket are included in antenna
price.

Options

Tiltable Mastholder for beam series XP40 + XP50

$ 100

Tiltable Mastholder for beam series XP70 + XP80

$130

Verticals

Broadband Verticals 3 - 30 MHz

Contact us for prices and for information on other frequency
ranges, such as e.g. 2 - 22 MHz